1. Field of the Invention
This invention relates to a seat sliding apparatus for a vehicle. Move particularly the present invention pertains to a vehicle seat sliding apparatus for moving the seat of the vehicle forward and backward by the driving power of an electric motor or through operation by a passenger.
2. Description of the Related Art
A conventional seat sliding apparatus for a vehicle is disclosed in Japanese Utility Model publication No. 4 (1992)-79732. The seat sliding apparatus disclosed in this document comprises a pair of upper rails fixed to the seat cushion of the vehicle, a pair of lower rails fixed to the vehicle floor and a pair of rollers which are each rotatably supported on a front portion and a rear portion of each of the upper rails.
Another conventional seat sliding apparatus for a vehicle is disclosed in Japanese Utility Model publication No. 3 (1991)-84237. The seat sliding apparatus disclosed in this document comprises a pair of lower rails fixed on a vehicle floor, a pair of upper rails fixed to a seat cushion and an intermediate rail disposed between one of the upper rails and the corresponding lower rail. The upper rails of the seat sliding apparatus are slid in two stages so as to be moved with a long stroke when a passenger rides in the vehicle.
In the seat sliding apparatus disclosed in the first document mentioned above, it is not possible to increase the moving stroke of the upper rails when a passenger is riding in the vehicle without making the upper rails longer. The upper rails cannot be made longer because of the standard scale of a vehicle cabin. On the other hand, the seat sliding apparatus disclosed in the latter document mentioned above is apt to be complicated.